Gates GT4 Primary Belt 640-8MR-25MM
The Gates PowerGrip GT4 25-mm Primary Belt is a direct OEM replacement and performance upgrade for the Sur Ron Ultra Bee electric dirt bike. Designed specifically for the flanged primary pulley system used on the Ultra Bee, this belt delivers increased torque capacity, stable tracking, and long life for riders putting serious miles on trails, tracks, and high-power builds across the U.S.
Unlike narrower belts like the OEM, the Ultra Bee platform relies on wider belt sprockets to manage higher torque loads. This 25 mm-wide GT4 belt gives you maximum belt width, ensuring proper pulley engagement without overhanging, misalignment, or accelerated edge wear.
The PowerGrip™ GT4™ construction uses a high-torque synchronous design with an optimized tooth profile that maintains correct clearance on flanged pulleys. Load is distributed evenly across the belt width, reducing heat buildup, minimizing friction, and preventing premature failure common with inferior aftermarket belts.
Whether you’re replacing a failed belt or upgrading ahead of time, this GT4 belt is a proven solution for stock and modified Ultra Bee setups that demand reliability and consistency.
Features
- Direct OEM replacement upgrade
- 25 mm wide belt for max width on OEM belt sprockets
- Gates PowerGrip GT4 high-torque carbon synchronous construction
- Optimized tooth profile for stable tracking on flanged pulleys
- Reduced friction for smoother power transfer and longer belt life
- Durable ethylene elastomer compound resists stretch and wear
- Ideal for stock and high-output builds
- Developed through GritShift R&D with Gates® engineers
- Manufactured in the USA
Fitment
Sur Ron Ultra Bee
*Bike in a box is not assembled, tuned or road tested *Bike in a box includes manufacturers limited warranty
The Gates PowerGrip GT4 25-mm Primary Belt is a direct OEM replacement and performance upgrade for the Sur Ron Ultra Bee electric dirt bike. Designed specifically for the flanged primary pulley system used on the Ultra Bee, this belt delivers increased torque capacity, stable tracking, and long life for riders putting serious miles on trails, tracks, and high-power builds across the U.S.
Unlike narrower belts like the OEM, the Ultra Bee platform relies on wider belt sprockets to manage higher torque loads. This 25 mm-wide GT4 belt gives you maximum belt width, ensuring proper pulley engagement without overhanging, misalignment, or accelerated edge wear.
The PowerGrip™ GT4™ construction uses a high-torque synchronous design with an optimized tooth profile that maintains correct clearance on flanged pulleys. Load is distributed evenly across the belt width, reducing heat buildup, minimizing friction, and preventing premature failure common with inferior aftermarket belts.
Whether you’re replacing a failed belt or upgrading ahead of time, this GT4 belt is a proven solution for stock and modified Ultra Bee setups that demand reliability and consistency.
Features
- Direct OEM replacement upgrade
- 25 mm wide belt for max width on OEM belt sprockets
- Gates PowerGrip GT4 high-torque carbon synchronous construction
- Optimized tooth profile for stable tracking on flanged pulleys
- Reduced friction for smoother power transfer and longer belt life
- Durable ethylene elastomer compound resists stretch and wear
- Ideal for stock and high-output builds
- Developed through GritShift R&D with Gates® engineers
- Manufactured in the USA
Fitment
Sur Ron Ultra Bee
